Process of obtaining nitrogen from air.



0. P. HURFORD.

PROCESS OF OBTAINING NITROGEN FROM AIR. APPLICATION FILED SEPT. 11,1905.

Patented Mar. 2, 1909.

O i M 1W 4 of Obtaining Nitrogen from Air; and

A FFIQ.

OLIVER PERRY HURFORD, OF CHICAGO, ILLINOIS.

' PROCESS OF OBTAINING NITROGEN FROM AIR.

Application filed September 11, 1905.

To all whom it may concern:

Be it known that I, OLIVER PERRY Hun- FORD, a citizen of the United States, and resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Procrisscps' o hereby declare. that the following is a full, clear, and exact description thereof.

This invention relates to a rocess of obtaining nitrogen from air throug 1 the combustion of any ordinary fuel, thereby supplyin the nitrogen in a practically pure state, irfiarge quantities at a low cost, to be used in the manufacture of any compound into which nitrogen enters as a constituent part. These fuels are com ounds of carbon, oxygen and hydrogen in the main, together with various other elements which are resent in small pro ortion and may be regarded as impurities. '1 e atmospheric air which constitutes the material from which the nitrogen is to be extracted is constituted by about three parts of oxygen by weight to ten parts of nitrogen, or about twenty-one parts of oxygen by vol ume to eighty parts of nitrogen. Certain small percentage of aqueous vapor, carbon dioxid and various other iln urities occur in this air, but these are in suofi small amounts that for the purpose in view they may be neglected.

As far as I am aware the only methods heretofore used for the production of free nitrogen in commercial quantities are as follows viz: 1st. Atmospheric air is passed through red hot copper filings or over red hot copper plates, where the oxygen is burned out and bcconu oxid of copper and the free nitrogen collected for use. 2nd. By liquefaction of the air and separation of the oxygen and nitrogen While this second process is the latest method for obtaining free nitrogen, it will be apparent that it is a very expensive method as compared with mine.

To separate the nitrogen from-the oxygen it is the purpose of the said process to transform the free oxygen into combined oxygen in the form of carbon dioxid (C0,) or aqueous vapor (H O) or both. This is done by the process of combustion, the elements hydrogen and carbon necessary for this combustion being most chea )ly obtained in the form of coal, gas, or. ot or combustible fuel. The purpose of effecting this chemical union of Specification of Letters Patent.

by fractional distillation. pressure, the amount of Patented March 2, 1909.

Serial No. 277,830.

oxygen with carbon and hydrogen is to transform it into a substance which is more easily l separable from the nitrogen than is oxygen l uncombined.

The first essential part of the apparatus employed in effecting the rocess 18, therefore, a combustion cham er suitable for maintaining the complete combustion of a fuel, with suitable means for introducing air into the combustion chamber, and suitable regulating devices for controlling the rate of flow of air, and the temperature and rate of l combustion.

By complete combustion is meant the comf bustion which Will result in the gaseous prodi ucts of combustion containing carbon dioxid (C0,), water vapor (H 0) and nitrogen, to

the practical exclusion of carbon monoxid (CO) oxygen in combined state, and hydrogen or unoxidized hydrocarbons. The presence of such gases in the products of combustion would result in a contamination of the resulting nitrogen, inasmuch as the apparatus is not designed to extract them. 'Close approach to perfect combustion can be attained by suitable regulation of air supply and temperature and proper feeding of the i fuel to the combustion chamber. Sulfur being almost invariably present in fuel will, during the process of complete combustion, be transformed mainly into sulfur dioxid 1 (S0 and in small part of sulfur trioxid (S0 which pass over as gases into the con densing chamber where they will be extracted in the manner to be described.

The compound, carbon dioxid, (CO is absorbed under ordinary pressure by water in equal quantities, i. e. the water absorbs its own bulk of the gas. By increasing the pressure to twicethe ordinary atmospheric gas absorbed will be twice the quantity of water in bulk. This l apparatus is so arranged by means of an extra forced draft at the furnace to increase the in the condenser at will, and thus the absorption of carbon dioxid Thus the carbonic acid gas, is abi sorbed, separating it entirely from the nit-rogen leaving it free from its oxygen. The next compound which is formed in the combustion i of the fuels above named, is water, through 1 the union of the hydrogen contained in illuminating fuels and oxygen, the Water appearlng in the form of steam, during com- 1 bustion. This steam is immediately coniOO ' ume of carbon dioxid is soluble in about onedensed into water. on entering the condenser and coming in contact with the cold water used therein.

The gaseous products are conducted through a channel into the condensation chamber, a suitable by-pass in this channel being provided for discharging the products of combustion to the chimney when the combustion is not perfect. 4

In the condensing chamber. of the apparatus the main objectis to separate the carbon dioxid from the nitrogen, this being accomlished through the property which carbon 'oxid ossesses of bein far more soluble in water t an nitrogen. lnder ordinary conditions of temperature and pressure one volvolume of water, the solubility increasing as the temperature is lowered and as the presexist in the sure is increased. The condensing chamber is so constructed that the gases flowing through it take a winding path, coming in contact at various points with sprays of water which serve the double purpose of cooling and absorption of the carbon dioxid. The water after performing this function accumulates in the bottom of the condenser, an overflow being provided which allows the continual removal of the water charged with the carbon dioxid.

The sulfur dioxid and sulfur trioxid which sorbed by the water forming sulfurous acid and sulfuric acid respectively, and are thereby extracted from the nitrogen. Y I

The aqueous va or which comes from the combustion chamber in coming in contact with the water sprays is cooled and condensed and is thereby carried away in the overflow. f

It is known that on account of the" resence of carbon dioxid and also of the su urous and sulfuric acids in the water, 1t 1s necessary as an essential feature of this apparatus.

thatit be constructed with a non-corrodible lining in. the condenser chamber.

In the accompanying drawing which illustrates the invention and which is an' elevation, partly in-section, A is'a furnace to which the carbonaceous fuel is fed and into which the atmospheric air, under any desired pressure is introduced, and in which the ste of combustion 1s carried'out, producing car on dioxid and other gaseous products of combustion. A flue B connects the furnace with acoveredtank 0 of the condenser. This condenser has water-s raying devices D, separated by plates I wflereby the gases are le alternately up and down in a crane-like movement so as to receive a thorough scrubbing. By means of these finely spraying devices mounted at intervals in the wavellke path of the gases, a thorou the water with the gases is obtained and also the temperature of the water is greatly products of combustion are abgh-contact of lowered, thereby increasing and absorbing action of the water upon the carbon dioxid, whereby with flow of water through the condenseras is carried on in my Process, the carbon dioxid is se arated from the nitrogen with sufficient rapi ity to permit the nitrogen to be obtamed at an economically practicable cost of production.

The condenser is rovided with a valvecontrolled drain-nozz c J, whereby the water charged with the-carbon dioxid is removed. The action of the condenser is to se arate the nitrogen from the carbon dioxid and from the impurities of the air as before described and then the nitrogen is led from the condenser by a flue E in communication with a fan;- casing F. v The nitrogen may be suitably collected in a vessel to receive it or may be at once led to'a place of intermixture with other elements or substances to form desired compounds.

In the drawings, the nitrogen is shown as conducted by a pi e G to an electric furnace H, in which may 5e placed a calcium carbid to produce calcium cynamid. It is obvious however that the nitrogen may be employed for other purposes than to form such compound.

Havingthus described my invention what claim is:

1. The process of obtaining from the an which consists in first burning a carbonaceous fuel in the presence of air of suflicient uantity for complete combustion to carbon dioxid and substantially free from carbon monoxid, then subjecting the gaseous productsto the condensing action of water to condense the-steam and separate the carbon dioxid. from the nitrogen and then leading off the nitrogen from the condensing chamber, substantially as described.

' The process of obtaining from atmospheric air which consists in burning a carbonaceous fuel by admittin air in amounts sufficient for complete com ustion of the fuel, leading the gaseous products of the condensing 4 a constant free nitrogen free nitrogen l combustion only when the same are substantially free of carbon monoxid from the combustion chamber directly to a suitable condensing as described.

the gaseous products substantially free from such carbon. monoxid directly to a condens-.'

ing chainber and entraining'said I gases in a chamber, and drawing the gasesv through said chamber in a continuous stream and then leading off the cient for complete combustion to carbon dioxid and without carbon monoxid, leadlng.

wave-like movement against separated finely invention 1 have hereunto set my hand at divided sprays of water continuouslysupplied Chicago in the county of Cook and State of to the chamber to condense the steam and to Illinois in the resence of two Witnesses.

rapidly and continuously absorb the carbon 0L1 R PERRY HURFORD; 5 dioxid and then drawing ofi the separated Witnesses:

nitrogen, substantially as described. NICHOLAS SCHNEIDER,

In testimony that I claim the foregoing FRANK O. SEYMOUR. 

